142 PALEONTOLOGY OF ILLINOIS. 



volutions, more strongly prominent carina, and in the flattened 

 band on the lower volution. 



Locality and position: Upper Coal Measures, LaSalle, Illinois. 



Collector, A. H. Worthen. 



No. 2603 of the Illinois State Museum. 



GENUS STRAPAKOLLUS. Montfort. 

 STRAPAROLLUS SUB-UMBILICATUS. (sp. nov.) 



PL XXIV, Figs. 3-3a-3b. 



Shell small, conical, whorls five, flattened above, rounded on 

 the periphery and sharply rounded below into the umbilicus. 



Umbilicus deep and rather wider than the diameter of the 

 outer volution near the aperture. Surface without ornamenta- 

 tion, except some faint lines of growth. 



Diameter of a medium size specimen 6 / 16 inch; height of the 

 same 5 / 16 inch. 



This little shell is closely related to the umbilicatus, Meek 

 and Worthen, of the Coal Measures, but differs from that spe- 

 cies in its comparatively narrow umbilicus, and much smaller 

 size. Of more than twenty specimens obtained, none attain a 

 diameter of more than half an inch. 



Position and locality: Calcareous shales of the Chester group, 

 near Evansville, Randolph county, 111. 



Collector, A. H. Worthen. 



No. 2602 of the Illinois State Museum. 



STRAPAROLLUS VARSOVIENSIS. (sp. nov.) 



PL XXV, Figs. 2-2a. 



Shell lenticular, whorls about four, gradually increasing in 

 size; spire moderately elevated above the body whorl. Volu- 

 tions somewhat flattened above, and regularly rounded on the 

 periphery, and more gently below into the umbilicus. 



The umbilicus is filled with the stony matrix, but is appar- 

 ently somewhat less in width than the diameter of the outer 

 whorl. 



The specimen is a cast in limestone, and no external mark- 

 ings are apparent. 



